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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Transactions of The Korean Institute of Electrical Engineers
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The Korean Institute of Electrical Engineers
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Volume & Issues
Volume 65, Issue 11 - Nov 2016
Volume 65, Issue 10 - Oct 2016
Volume 65, Issue 9 - Sep 2016
Volume 65, Issue 8 - Aug 2016
Volume 65, Issue 7 - Jul 2016
Volume 65, Issue 6 - Jun 2016
Volume 65, Issue 5 - May 2016
Volume 65, Issue 4 - Apr 2016
Volume 65, Issue 3 - Mar 2016
Volume 65, Issue 2 - Feb 2016
Volume 65, Issue 1 - Jan 2016
Selecting the target year
Improvement of the Load Forecasting Accuracy by Reflecting the Operation Rates of Industries on the Consecutive Holidays
Lim, Nam-Sik ; Lee, Sang-Joong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1115~1120
DOI : 10.5370/KIEE.2016.65.7.1115
This paper presents the daily load forecasting for special days considering the rate of operation of industrial consumers. The authors analyzed the power consumption pattern for both the special and ordinary days according to the contract power classification of industrial consumers, and selected 400~600 specific consumers for which the rates of operation during special days are needed. Load forecasting for 2014 special days considering the rate of operation of industrial consumers showed a noticeable improvement on forecasting error of daily peak demand, which proved the effectiveness of the survey for the rates of operation during special days of industrial consumers.
A Study on the Overcurrent Relay Modeling and Protective Coordination for Overload in Domestic AC Electrical Railway System
Kim, Hyun-Dong ; Cho, Gyu-Jung ; Huh, Seung-Hoon ; Kim, Chul-Hwan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1121~1127
DOI : 10.5370/KIEE.2016.65.7.1121
In this paper, modeling of overcurrent relay(OCR) to protect domestic AC electric railway Auto Transformer(AT) feeding system and operation characteristic analysis on overload condition are described. The target system of this paper is actual site where overload trip of circuit breaker occurs frequently. Because this AT feeding system is made of parallel single track which had a load(electric train) respectively, and is connected with only T phase of Scott Transformer. In addition, this system has been feeding 66kV voltage by KEPCO, not 154kV. We focus on protective coordination of Scott Transformer primary side and secondary side OCR for Korea single track AC electrical railway system in operation currently. We modeled single track AT feeding system and OCR. Also we performed faults and overload analysis for verification of OCR`s setting values and system modeling. To analyze above mentioned research, we used PSCAD/EMTDC software tool.
Demand Response of Large-Scale General and Industrial Customer using In-House Pricing Model
Kim, Min-Jeong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1128~1134
DOI : 10.5370/KIEE.2016.65.7.1128
Demand response provides customer load reductions based on high market prices or system reliability conditions. One type of demand response, price-based program, induces customers to respond to changes in product rates. However, there are large-scale general and industrial customers that have difficulty changing their energy consumption patterns, even with rate changes, due to their electricity demands being commercial and industrial. This study proposes an in-house pricing model for large-scale general and industrial customers, particularly those with multiple business facilities, for self-regulating demand-side management and cost reduction. The in-house pricing model charges higher rates to customers with lower load factors by employing peak to off-peak ratios in order to reduce maximum demand at each facility. The proposed scheme has been applied to real world and its benefits are demonstrated through an example.
A Mechanism of IPP`s(Coal Fired) Optimal Power Generation According to Introduction of RPS(Renewable Portfolio Standard)
Ha, Sun-Woo ; Lee, Sang-Joong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1135~1143
DOI : 10.5370/KIEE.2016.65.7.1135
A private company`s 1,000 MW coal-fired power plant will be the first coal-fired power plant that was included in the 5th `Basic Plan on Electricity Demand and Supply` (2010). Now it is facing the task to abide by the RPS(Renewable Portfolio Standard) policy after commercial operation. If they fail to supply the necessary REC (Renewable Energy Certificate) mandated by the RPS policy, they are subject to be fined by the government and forced to modify the cost function to reflect the burden. Eventually the company`s coal-fired power plant will be forced to reduce generation to maximize profit because the amount of electricity generated by the power plant and the REC obligation is positively correlated. This paper analyzed the change of cost function of private coal-fired power plant according to the introduction of RPS policy from the viewpoint of private company, and finally proposed the optimal generation to maximize the profit of private coal-fired power plant under the current RPS policy.
24-Hour Load Forecasting For Anomalous Weather Days Using Hourly Temperature
Kang, Dong-Ho ; Park, Jeong-Do ; Song, Kyung-Bin ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1144~1150
DOI : 10.5370/KIEE.2016.65.7.1144
Short-term load forecasting is essential to the electricity pricing and stable power system operations. The conventional weekday 24-hour load forecasting algorithms consider the temperature model to forecast maximum load and minimum load. But 24-hour load pattern forecasting models do not consider temperature effects, because hourly temperature forecasts were not present until the latest date. Recently, 3 hour temperature forecast is announced, therefore hourly temperature forecasts can be produced by mathematical techniques such as various interpolation methods. In this paper, a new 24-hour load pattern forecasting method is proposed by using similar day search considering the hourly temperature. The proposed method searches similar day input data based on the anomalous weather features such as continuous temperature drop or rise, which can enhance 24-hour load pattern forecasting performance, because it uses the past days having similar hourly temperature features as input data. In order to verify the effectiveness of the proposed method, it was applied to the case study. The case study results show high accuracy of 24-hour load pattern forecasting.
Analysis of Electricity Cost Saving Effect by the Optimal load shifting Operation with 1MWh Redox Flow Battery
Baek, Ja-Hyun ; Ko, Eun-Young ; Kang, Tae-Hyuk ; Lee, Han-Sang ; Cho, Soo-Hwan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1151~1160
DOI : 10.5370/KIEE.2016.65.7.1151
In recent years, the energy storage systems such as LiB, NaS, RFB(Redox-Flow Battery), Super- capacitor, pumped hydro storage, flywheel, CAES(Compressed Air Energy Storage) and so on have received great attention as practical solutions for the power supply problems. They can be used for various purpose of peak shaving, load leveling and frequency regulation, according to the characteristics of each ESS(energy storage system). This paper will focus at 1 MWh RFB system, which is being developed through the original technology project of energy material. The output of ESS is mainly characterized by C-rate, which means that the total rated capacity of battery will be delivered in 1 hour. And it is a very important factor in the ESS operation scheduling. There can be several options according to the operation intervals 15, 30 and 60minutes. The operation scheduling is based on the optimization to minimize the daily electricity cost. This paper analyzes the cost-saving effects by the each operating time-interval in case that the RFB ESS is optimally scheduled for peak shaving and load leveling.
Operating Method of BESS for Providing AGC Frequency Control Service Considering Its Availability Maximization
Choi, Woo Yeong ; Yu, Ga Ram ; Kook, Kyung Soo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1161~1168
DOI : 10.5370/KIEE.2016.65.7.1161
Battery energy storage system(BESS) attract the attention of the power system operators with its fast response to a disturbance in spite of its limited energy capacity. This paper proposes the operating method of BESS for following the Automatic Generation Control(AGC) frequency control which is centrally distributed by a system operator. As BESS needs to just meet the control requirement from the system operator, it should be able to properly manage the state of charge(SOC) of BESS to be available to control signal. For doing these, the proposed method distributes the control requirement to available batteries in proportion to its SOC. In addition, unavailable batteries are controlled to recover the SOC to an appropriate range, and the recovering power is supplied by available batteries meeting the control requirement. Moreover, the proposed method manages the efficiency of power conversion system (PCS) by limiting the number of PCS to be assigned for the low control requirement. Finally, the case studies are carried out to verify the effectiveness of proposed strategy.
Integrated Control Strategy of Multiple BESS for providing Primary Frequency Control
Yu, Ga Ram ; Choi, Woo Yeong ; Kook, Kyung Soo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1169~1175
DOI : 10.5370/KIEE.2016.65.7.1169
As an Increased penetration level of renewable resources has caused concerns about primary frequency response, an increase in BESS(Battery Energy Storage System) capacity has been expected because of its fast response to the disturbances in the power system. This paper proposes the Integrated Control Strategy of multiple BESS for effectively providing the primary frequency control in the bulk power systems by coordinating the response, SOC and its recovery of BESS. The proposed strategy prevents multiple BESS from providing exceeding response and keeps the balance between SOC of multiple BESS. In addition, It would recover the SOC of BESS efficiently. The effectiveness of the proposed strategy is verified through various case studies employing Korean power system.
NeW Output Voltage Control Scheme Based on SoC Variation of BESS Applicable for Stand-alone DC Microgrid
Yu, Seung-Yeong ; Kim, Hyun-Jun ; Han, Byung-Moon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1176~1185
DOI : 10.5370/KIEE.2016.65.7.1176
This paper proposes a new output voltage control scheme based on the SoC variation of the battery energy storage system (BESS) applicable for the stand-alone DC microgrid. The proposed control scheme provides relatively lower variation of the DC grid voltage than the conventional droop method. The performance of proposed control scheme was verified through computer simulations for a typical stand-alone DC microgrid which consists of BESS, photo-voltaic (PV) panel, engine generator (EG), and DC load. A scaled hardware prototype for the stand-alone DC microgrid with DSP controller was set up in the lab, and the proposed control algorithm was installed in the DSP controller. The test results were compared with the simulation results for performance verification and actual system implementation.
Techniques to Diagnose Short-Circuit Faults in the Switching Mode Power Supply for Display
Lee, Jae-Won ; Chun, Tae-Won ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1186~1192
DOI : 10.5370/KIEE.2016.65.7.1186
This paper proposes techniques to diagnose short-circuit faults of both the diodes and power FET in switching mode power supply (SMPS) by using a simple analog tester. The diodes in full-bridge rectifier, power FET, switching transformer, and some sensors are modelled with resistor. The total resistance value measured at the input terminal of a SMPS is analyzed when the short-circuit faults of diodes in a full bridge rectifier or power FET are occurred. The short-circuit faults of one or two diodes in a full bridge rectifier, power FET, and both the diodes in a full bridge rectifier and power FET can be detected by a range of total resistance, which is measured by the analog tester. Through experiments, the theoretical analysis for total resistance under short-circuit faults can be verified.
Droop Control to Compensate Load Voltage Unbalance for Inverter-based Distributed Generations with Unequal Impedance Lines
Yang, Won-Mo ; Kim, Hyun-Jun ; Han, Byung-Moon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1193~1203
DOI : 10.5370/KIEE.2016.65.7.1193
This paper proposes a droop control scheme to compensate the unbalanced line-to-line voltage of unbalanced 3-phase load which is coupled with two inverter-based distributed generations through unequal impedance lines. Unbalanced line-to-line load voltages occur due to using single-phase loads, which brings about bad effects on the coupled inverters and the distributed generations. In order to compensate the unbalanced line-to-line voltages, a positive sequence voltage control was used for sharing the active and reactive power and a negative sequence control was used for reducing the negative sequence voltage. The feasibility of the proposed scheme was first verified by computer simulations, and then experiments with a hardware set-up built in the lab. The experimental results were compared with the simulation results to confirm the feasibility of the proposed scheme.
Compensation Method of Current Measurement Error for Vector-Controlled Inverter of 2-Phase Induction Motor
Lee, Ho-Jun ; Yoon, Duck-Yong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1204~1210
DOI : 10.5370/KIEE.2016.65.7.1204
The phase currents must be accurately measured to achieve the instantaneous torque control of AC motors. In general, those are measured using the current sensors. However, the measured current signals can include the offset errors and scaling errors by several components such as current sensors, analog amplifiers, noise filter circuits, and analog-to-digital converters. Therefore, the torque-controlled performance can be deteriorated by the current measurement errors. In this paper we have analyzed the influence caused by vector control of 2-phase induction motor when two errors are included in measured phase currents. Based on analyzed results, the compensation method is proposed without additional hardware. The proposed compensation method was applied vector-controlled inverter for 2-phase induction motor of 360[W] class and verified through computer simulations and experiments.
Analysis of Inductively Coupled Plasma using Electrostatic Probe and Fluid Simulation
Cha, Ju-Hong ; Lee, Ho-Jun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1211~1217
DOI : 10.5370/KIEE.2016.65.7.1211
Discharge characteristics of inductively coupled plasma were investigated by using electrostatic probe and fluid simulation. The Inductively Coupled Plasma source driven by 13.56 Mhz was prepared. The signal attenuation ratios of the electrostatic probe at first and second harmonic frequency was tuned in 13.56Mhz and 27.12Mhz respectively. Electron temperature, electron density, plasma potential, electron energy distribution function and electron energy probability function were investigated by using the electrostatic probe. Experiment results were compared with the fluid simulation results. Ar plasma fluid simulations including Navier-Stokes equations were calculated under the same experiment conditions, and the dependencies of plasma parameters on process parameters were well agreed with simulation results. Because of the reason that the more collision happens in high pressure condition, plasma potential and electron temperature got lower as the pressure was higher and the input power was higher, but Electron density was higher under the same condition. Due to the same reason, the electron energy distribution was widening as the pressure was lower. And the electron density was higher, as close to the gas inlet place. It was found that gas flow field significantly affect to spatial distribution of electron density and temperature.
The Influence of Surface Modified Nano Alumina for Electrical Treeing in Epoxy Insulation
Park, Jae-Jun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1218~1224
DOI : 10.5370/KIEE.2016.65.7.1218
This paper presents the results of a study on the effect of surface modified alumina nanocomposites on electrical tree growth in epoxy insulation. Treeing experiments were conducted at a fixde AC voltage (500kV/mm, 10kV/60Hz)on unfilled epoxy sample as well as epoxy nanocomposites of 4 types with different loading and surface modified GDE gram. Time for tree growth as well as tree propagation length were studied. The results show that there is a significant improvement tree propagation time compare unfilled epoxy to epoxy nano alumina composites. Different tree propagation shapes as well as slower tree growth with 4 types nano alumina composites were observed.
Irradiant Energy into an Eye from a Flash Light
Park, Seung-Man ; Han, Seungoh ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1225~1230
DOI : 10.5370/KIEE.2016.65.7.1225
Since a flash light produces enormous amount of photon energy in short time, not only electro-optic and infrared(EO/IR) systems utilized for Intelligence Surveillance Target Acquisition and reconnaissance(ISTAR) activities but also the people of a combat field can be severely influenced by a high flash light bursting in front of them. The people who bumped into a flash could not escape such enormous amount of photon energy, resulting in being blind temporarily or even permanently. In order to investigate the effect of a high flash source on a human eye, it is essential to know how much photon energy be incident into an eye from the flash source. In this paper, the model of irradiated photon energy to individuals from some flashes is proposed. The proposed irradiated photon energy per unit area of retina is based on taking the situation to be modeled as a simple EO system in front of a flash light. The validity of proposed model was proved by the application of the model to human on the surface of the earth with the well known light source, the Sun. The model of this study can be utilized to simulate the retinal intensity and energy of a flash for various conditions such as the illumination levels, the distance from a flash busting site, luminous intensity and time of a flash.
A Study on Estimation of Scoliosis using Electromyography Sensor
Choi, Dae-Yeong ; Nam, Hyun-Do ; Kim, Kyung-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1231~1235
DOI : 10.5370/KIEE.2016.65.7.1231
In this study, it measures electromyogram to estimate scoliosis by using sensors in both sides of spinal erector muscle. A device is measured raw data to input mcu through a filter and amplifier. MCU is named "arduino" that is calculated muscle activity with algorithm by inputting data. By comparing with both sides of spinal erector muscle`s activity, it studies about estimation of scoliosis
Application of Data Mining for Biomedical Data Processing
Shon, Ho-Sun ; Kim, Kyoung-Ok ; Cha, Eun-Jong ; Kim, Kyung-Ah ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1236~1241
DOI : 10.5370/KIEE.2016.65.7.1236
Cancer has been the most frequent in Korea, and pathogenesis and progression of cancer have been known to be occurred through various causes and stages. Recently, the research of chromosomal and genetic disorder and the research about prognostic factor to predict occurrence, recurrence and progress of chromosomal and genetic disorder have been performed actively. In this paper, we analyzed DNA methylation data downloaded from TCGA (The Cancer Genome Atlas), open database, to research bladder cancer which is the most frequent among urinary system cancers. Using three level of methylation data which had the most preprocessing, 59 candidate CpG island were extracted from 480,000 CpG island, and then we analyzed extracted CpG island applying data mining technique. As a result, cg12840719 CpG island were analyzed significant, and in Cox`s regression we can find the CpG island with high relative risk in comparison with other CpG island. Shown in the result of classification analysis, the CpG island which have high correlation with bladder cancer are cg03146993, cg07323648, cg12840719, cg14676825 and classification accuracy is about 76%. Also we found out that positive predictive value, the probability which predicts cancer in case of cancer was 72.4%. Through the verification of candidate CpG island from the result, we can utilize this method for diagnosing and treating cancer.
Comparison of Heel-rocking Time Between Young Women and Elderly Women
Yun, Ju-seok ; Kim, Ji-Won ; Kwon, Yu-Ri ; Heo, Jae-Hoon ; Jeon, Hyeong-Min ; Jeon, Hee-Jun ; Eom, Gwang-Moon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1242~1246
DOI : 10.5370/KIEE.2016.65.7.1242
Heel rocking phase in gait cycle is from initial contact to forefoot contact. The purpose of this study was to investigate the effect of age on heel rocking time. Seven young women (
) and seven elderly women (
) participated in this study. Subjects wore the shoes equipped with pressure sensors and walked along 10 m walkway at comfortable speeds. Stride time, stance time, and heel rocking time were compared between groups. Stride time was not different between groups (p
An Effect of Sampling Rate to the Time and Frequency Domain Analysis of Pulse Rate Variability
Yang, Yoon La ; Shin, Hangsik ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1247~1251
DOI : 10.5370/KIEE.2016.65.7.1247
This study aims to investigate the effect of sampling frequency to the time domain and frequency domain analysis of pulse rate variability (PRV). Typical time domain variables - AVNN, SDNN, SDSD, RMSSD, NN50 count and pNN50 - and frequency domain variables - VLF, LF, HF, LF/HF, Total Power, nLF and nHF - were derived from 7 down-sampled (250 Hz, 100 Hz, 50 Hz, 25 Hz, 20 Hz, 15 Hz, 10 Hz) PRVs and compared with the result of heart rate variability of 10 kHz-sampled electrocardiogram. Result showed that every variable of time domain analysis of PRV was significant at 25 Hz or higher sampling frequency. Also, in frequency domain analysis, every variable of PRV was significant at 15 Hz or higher sampling frequency.
Acquisition of Multi-channel Biomedical Signals Based on Internet of Things
Kim, Jeong-Hwan ; Jeung, Gyeo-Wun ; Lee, Jun-Woo ; Kim, Kyeong-Seop ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1252~1256
DOI : 10.5370/KIEE.2016.65.7.1252
Internet of Things(IoT)-devices are now expanding inter-connecting networking technologies to invent healthcare monitoring system especially for assessing physiological conditions of the chronically-ill patients those with cardiovascular diseases. Hence, IoT system is expected to be utilized for home healthcare by dedicating the original usage of IoT devices to collect the biomedical data such as electrocardiogram(ECG) and photoplethysmography(PPG) signal. The aim of this work is to implement health monitoring system by integrating IoT devices with Raspberry-pi components to measure and analyze ECG and the multi-channel PPG signals. The acquired data and fiducial features from our system can be transmitted to mobile devices via wireless networking technology to support the concept of tele-monitoring services based on IoT devices.
A Study of Medication Adherence Using Textile Proximity Sensor
Ho, Jong Gab ; Wang, Changwon ; Min, Se Dong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1257~1262
DOI : 10.5370/KIEE.2016.65.7.1257
The purpose of this study is to evaluate whether to take a medicine based on a measuring data using textile proximity sensor. We developed a proximity sensor of ring type using conductive textile, and acquired a data in accordance with the quantity of each pills. To evaluate our approach, we designed an experimental protocol that is counting pills subtracting the one which contains range of 0 T(Tablet, 4,100mg) from 20 T. And, The experiments were performed a nine times in the same way. In order to remove a noise and smoothen data, data preprocessing were performed using resampling method and moving average filter which has ten points. Then, we calculated a linear trend line equation, and analyzed a correlation between pill quantity and trend line equation. As a results, correlation coefficient was shown at 0.833 through using a Spearman`s correlation method and we could be determined that data was continuos decreases when take a medicine.
A Design of Dangerous Sound Detection Engine of Wearable Device for Hearing Impaired Persons
Byun, Sung-Woo ; Lee, Soek-Pil ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1263~1269
DOI : 10.5370/KIEE.2016.65.7.1263
Hearing impaired persons are exposed to the danger since they can`t be aware of many dangerous situations like fire alarms, car hones and so on. Therefore they need haptic or visual informations when they meet dangerous situations. In this paper, we design a dangerous sound detection engine for hearing impaired. We consider four dangerous indoor situations such as a boiled sound of kettle, a fire alarm, a door bell and a phone ringing. For outdoor, two dangerous situations such as a car horn and a siren of emergency vehicle are considered. For a test, 6 data sets are collected from those six situations. we extract LPC, LPCC and MFCC as feature vectors from the collected data and compare the vectors for feasibility. Finally we design a matching engine using an artificial neural network and perform classification tests. We perform classification tests for 3 times considering the use outdoors and indoors. The test result shows the feasibility for the dangerous sound detection.
Regulation Control of Two-Link Robot Arm with the Input Constraint using Sum of Squares Method
Jeong, Jin-Gang ; Chwa, Dongkyoung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1270~1276
DOI : 10.5370/KIEE.2016.65.7.1270
This paper proposes the controller design for regulation control of two-link robot arm using sum of squares (SOS) control method that takes into account the input constraint. The existing studies of two link robotic arm system used a linear model of all the non-linearity of the system is linearized. For a linear controller, since the model of the system is simplified, it is possible to design a controller in consideration of constraints on the disturbance. However, there is a limit to the performance using a linearized model for a system with a complex nonlinear properties. To compensate for this in the case of using a fuzzy LMI method, it is necessary to have a large number of linear models and thus there is a disadvantage that the system becomes complicated. To solve these problems, we represents a two-link robot arm system with a polynomial model using a Taylor series expansion and design the controller considering the case where the magnitude of the control input is limited using SOS method. We demonstrate by simulations the feasibility of the proposed algorithm.
Capturing Data from Untapped Sources using Apache Spark for Big Data Analytics
Nichie, Aaron ; Koo, Heung-Seo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1277~1282
DOI : 10.5370/KIEE.2016.65.7.1277
The term "Big Data" has been defined to encapsulate a broad spectrum of data sources and data formats. It is often described to be unstructured data due to its properties of variety in data formats. Even though the traditional methods of structuring data in rows and columns have been reinvented into column families, key-value or completely replaced with JSON documents in document-based databases, the fact still remains that data have to be reshaped to conform to certain structure in order to persistently store the data on disc. ETL processes are key in restructuring data. However, ETL processes incur additional processing overhead and also require that data sources are maintained in predefined formats. Consequently, data in certain formats are completely ignored because designing ETL processes to cater for all possible data formats is almost impossible. Potentially, these unconsidered data sources can provide useful insights when incorporated into big data analytics. In this project, using big data solution, Apache Spark, we tapped into other sources of data stored in their raw formats such as various text files, compressed files etc and incorporated the data with persistently stored enterprise data in MongoDB for overall data analytics using MongoDB Aggregation Framework and MapReduce. This significantly differs from the traditional ETL systems in the sense that it is compactible regardless of the data formats at source.
Localization of Mobile Robots by Full Detection of Ceiling Outlines
Kim, Young-Gyu ; Park, Tae-Hyoung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1283~1289
DOI : 10.5370/KIEE.2016.65.7.1283
In this paper, we propose a new localization system using ceiling outlines. We acquire the entire ceiling image by using fisheye lens camera, and extract the lines by binarization and segmentation. The optical flow algorithm is then applied to identify the ceiling region from the segmented regions. Finally we obtain the position and orientation of the robot by the center position and momentum of ceiling region. Since we use the fully detected outlines, the accuracy and reliability of the localization system is improved. The experimental result are finally presented to show the effectiveness of the proposed method.
Diagnosis Engineering of Grounding System to Reduce Noise Signals
Cho, Dae-Hoon ; Lee, Ki-Sik ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1290~1294
DOI : 10.5370/KIEE.2016.65.7.1290
In this study, we investigate the sources of system malfunctions by measuring and diagnosing various surges and noise signals from grounding systems for electrical and electronic systems and installations in order to ensure the reliability and stability of the system operations. We measured performance or structural problems detected in the grounding systems currently in operation and analyzed the measured data in order to eliminate noise currents and interferences causing the systems to malfunction and be damaged. Based on the analysis results, we proposed improving grounding systems and the wiring arrangements most appropriate for the grounding systems and carried out the installations as per the proposed engineering. We verified that the proposed engineering made the status of system operations improved by measuring the ground noise signals during the system operations and comparing them before and after improvements being carried out.
Development of Black Box for Home Battery Energy Storage System Connected with Solar Energy Generation
Kim, Sang-Dong ; Park, Ji-Ho ; Kim, Dong-Wan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1295~1302
DOI : 10.5370/KIEE.2016.65.7.1295
In this paper, a black box, which is provided the reliability and user safety of home battery energy storage system connected with solar energy generation, is developed. In the developed scheme, a status and diagnosis data of battery management system, power conditioning system, solar energy generation and grid is measured. This status and diagnosis data is stored and displayed in the developed black box. In addition, this status and diagnosis data is stored and displayed in a monitoring system and a smart phone of user. A performance evaluation of the developed black box is carried out using emulator of home battery energy storage system connected with solar energy generation. Consequently, the developed black box is proved its superiority of the reliability and user safety.
A Study on the Rail Rupture Detection by the Return Current
KIM, Yong-Kyu ; YOON, Yong-Ki ; LEE, Jong-Hyun ; KWAK, Woo-Hyun ; LEE, Kwang-Hee ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1303~1310
DOI : 10.5370/KIEE.2016.65.7.1303
The track circuit carries out a train detection using a electrical closed loop, and incidentally it detects the rail rupture using the track circuit current flowing rail. However, in the case of the axle counter or the Radio based train control system, it requires a new way for detecting the rail rupture because of not using the track circuit. To solve this problem, it periodically checks non-steady state of rail by the track inspection car. but real-time detection of the rail rupture is impossible. Therefore, this paper analyzed feasibility to realize a real-time detection of rail rupture by using the return current.
A Study on the Optimum Selection of the Power Factor Compensation Condenser According to the Improved Efficiency of Induction Motor
Kim, Jong-Gyeum ;
The Transactions of The Korean Institute of Electrical Engineers, volume 65, issue 7, 2016, Pages 1311~1315
DOI : 10.5370/KIEE.2016.65.7.1311
Induction motor requires a rotating magnetic field for rotation. Current required to generate the rotating magnetic field is immediately magnetizing current. This magnetizing current is associated with the reactive power. Induction motor is always required reactive power. If reactive power is supplied only to the power supply side, the power factor is low. Therefore, it is to compensate the power factor by connecting capacitors in parallel to the motor terminal. If the capacitor current is greater than the magnetizing current of the motor, there is a possibility that the self-excitation occurs. High voltage generated by the self-excitation leads to insulation failure on the motor. So it is necessary to calculate the power factor correction capacitor capacity the most suitable to the extent that the magnetizing current does not exceed the capacitor current. In this study, we first computed the magnetization current and the reactive power of the induction motor and then calculates a limit of the maximum power factor by comparing the magnetizing current and the capacitor current installed in order to achieve the target power factor.