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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Electrical Engineering and Technology
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The Korean Institute of Electrical Engineers
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Volume & Issues
Volume 8, Issue 6 - Nov 2013
Volume 8, Issue 5 - Sep 2013
Volume 8, Issue 4 - Jul 2013
Volume 8, Issue 3 - May 2013
Volume 8, Issue 2 - Mar 2013
Volume 8, Issue 1 - Jan 2013
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Novel Techniques for Real Time Computing Critical Clearing Time SIME-B and CCS-B
Dinh, Hung Nguyen ; Nguyen, Minh Y. ; Yoon, Yong Tae ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 197~205
DOI : 10.5370/JEET.2013.8.2.197
Real time transient stability assessment mainly depends on real-time prediction. Unfortunately, conventional techniques based on offline analysis are too slow and unreliable in complex power systems. Hence, fast and reliable stability prediction methods and simple stability criterions must be developed for real time purposes. In this paper, two new methods for real time determining critical clearing time based on clustering identification are proposed. This article is covering three main sections: (i) clustering generators and recognizing critical group; (ii) replacing the multi-machine system by a two-machine dynamic equivalent and eventually, to a one-machine-infinite-bus system; (iii) presenting a new method to predict post-fault trajectory and two simple algorithms for calculating critical clearing time, respectively established upon two different transient stability criterions. The performance is expected to figure out critical clearing time within 100ms-150ms and with an acceptable accuracy.
A New Method for Monitoring Local Voltage Stability using the Saddle Node Bifurcation Set in Two Dimensional Power Parameter Space
Nguyen, Van Thang ; Nguyen, Minh Y. ; Yoon, Yong Tae ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 206~214
DOI : 10.5370/JEET.2013.8.2.206
This paper proposes a new method for monitoring local voltage stability using the saddle node bifurcation set or loadability boundary in two dimensional power parameter space. The method includes three main steps. First step is to determine the critical buses and the second step is building the static voltage stability boundary or the saddle node bifurcation set. Final step is monitoring the voltage stability through the distance from current operating point to the boundary. Critical buses are defined through the right eigenvector by direct method. The boundary of the static voltage stability region is a quadratic curve that can be obtained by the proposed method that is combining a variation of standard direct method and Thevenin equivalent model of electric power system. And finally the distance is computed through the Euclid norm of normal vector of the boundary at the closest saddle node bifurcation point. The advantage of the proposed method is that it gets the advantages of both methods, the accuracy of the direct method and simple of Thevenin Equivalent model. Thus, the proposed method holds some promises in terms of performing the real-time voltage stability monitoring of power system. Test results of New England 39 bus system are presented to show the effectiveness of the proposed method.
Multi-objective Unbalanced Distribution Network Reconfiguration through Hybrid Heuristic Algorithm
Mahendran, G. ; Sathiskumar, M. ; Thiruvenkadam, S. ; Lakshminarasimman, L. ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 215~222
DOI : 10.5370/JEET.2013.8.2.215
Electrical power distribution systems are critical links between the utility and customer. In general, power distribution systems have unbalanced feeders due to the unbalanced loading. The devices that dependent on balanced three phase supply are affected by the unbalanced feeders. This necessitates the balancing of feeders. The main objective of reconfiguration is to balance the loads among the phases subject to constraints such as load flow equations, capacity and voltage constraints and to reduce the real power loss, while subject to a radial network structure in which all loads must be energized. Therefore, the distribution system reconfiguration problem has been viewed as multi-objective problem. In this paper, the hybrid heuristic algorithm has been used for reconfiguration, which is the combination of fuzzy and greedy algorithms. The purpose of the introduction of greedy is to refrain the searching for the period of phase balancing. The incorporation of fuzzy helps to take up more objectives amid phase balancing in the searching. The effectiveness of the proposed method is demonstrated through modified IEEE 33 bus and modified IEEE 125 bus radial distribution system.
Value-based Distributed Generation Placements for Reliability Criteria Improvement
Heidari, Morteza ; Banejad, Mahdi ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 223~229
DOI : 10.5370/JEET.2013.8.2.223
Restructuring and recent developments in the power system and problems arising from construction and maintenance of large power plants, increasing amount of interest in distributed generation (DG) source. Distributed generation units due to specifications, technology and location network connectivity can improve system and load point reliability indices. In this paper, the allocation and sizing of DG in distribution networks are determined using optimization. The objective function of the proposed method is to improve customer-based reliability indices at lowest cost. The placement and size of DGs are optimized using a Genetic Algorithm (GA). To evaluate the proposed algorithm, 34-bus IEEE test system, is used. The results illustrate efficiency of the proposed method.
PI-CCC Based Switched Reluctance Generator Applications for Wind Power Generation Using MATLAB/SIMULINK
Kaliyappan, Kannan ; Padmanabhan, Sutha ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 230~237
DOI : 10.5370/JEET.2013.8.2.230
This paper presents a novel nonlinear model of Switched Reluctance Generator (SRG) based on wind Energy Conversion system. Closed loop control with based Proportional Integrator current Chopping Control machine model is used. A Power converter in SRG can be controlled by using PI-CCC proposed model, and can be produced maximum power efficiency and minimize the ripple contents in the output of SRG. A second power converter namely PI based controlled PWM Inverter is used to interface the machine to the Grid. An effective control technique for the inverter, based on the pulse width modulation (PWM) scheme, has been developed to make the line voltage needs less power switching devices and each pair of turbine the generated active power starts increasing smoothly. This proposed control scheme feasibility and validity are simulated on SIMULINK/SIM POWER SYSTEMS only.
Optimized Installation and Operations of Battery Energy Storage System and Electric Double Layer Capacitor Modules for Renewable Energy Based Intermittent Generation
Min, Sang Won ; Kim, Seog Ju ; Hur, Don ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 238~243
DOI : 10.5370/JEET.2013.8.2.238
In this paper, a novel approach for optimized installation and operations of battery energy storage system (BESS) and electric double layer capacitor (EDLC) modules for the renewable energy based intermittent generation is presented for them to be connected with an electric power grid. In order to make use of not merely the high energy density of battery but also the high power density of EDLC modules, it is very useful to devise the hybrid system which combines BESS and EDLC modules. The proposed method adopts the linear programming to calculate the optimized capacity as well as the quadratic programming to transmit the optimal operational signals to BESS and EDLC modules. The efficiency of this methodology will be demonstrated in the experimental study with the real data of wind speed in Texas.
Impact of Electric Vehicle Penetration-Based Charging Demand on Load Profile
Park, Woo-Jae ; Song, Kyung-Bin ; Park, Jung-Wook ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 244~251
DOI : 10.5370/JEET.2013.8.2.244
This paper presents a study the change of the load profile on the power system by the charging impact of electric vehicles (EVs) in 2020. The impact of charging EVs on the load demand is determined not only by the number of EVs in usage pattern, but also by the number of EVs being charged at once. The charging load is determined on an hourly basis using the number of the EVs based on different scenarios considering battery size, model, the use of vehicles, charging at home or work, and the method of charging, which is either fast or slow. Focusing on the impact of future load profile in Korea with EVs reaching up 10 and 20 percentage, increased power demand by EVs charging is analyzed. Also, this paper analyzes the impact of a time-of-use (TOU) tariff system on the charging of EVs in Korea. The results demonstrate how the penetration of EVs increases the load profile and decreases charging demand by TOU tariff system on the future power system.
TCSC Nonlinear Adaptive Damping Controller Design Based on RBF Neural Network to Enhance Power System Stability
Yao, Wei ; Fang, Jiakun ; Zhao, Ping ; Liu, Shilin ; Wen, Jinyu ; Wang, Shaorong ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 252~261
DOI : 10.5370/JEET.2013.8.2.252
In this paper, a nonlinear adaptive damping controller based on radial basis function neural network (RBFNN), which can infinitely approximate to nonlinear system, is proposed for thyristor controlled series capacitor (TCSC). The proposed TCSC adaptive damping controller can not only have the characteristics of the conventional PID, but adjust the parameters of PID controller online using identified Jacobian information from RBFNN. Hence, it has strong adaptability to the variation of the system operating condition. The effectiveness of the proposed controller is tested on a two-machine five-bus power system and a four-machine two-area power system under different operating conditions in comparison with the lead-lag damping controller tuned by evolutionary algorithm (EA). Simulation results show that the proposed damping controller achieves good robust performance for damping the low frequency oscillations under different operating conditions and is superior to the lead-lag damping controller tuned by EA.
A Boundary Protection for Power Distribution Line Based on Equivalent Boundary Effect
Zhang, Xin ; Mu, Long-Hua ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 262~270
DOI : 10.5370/JEET.2013.8.2.262
A boundary protection method for power distribution line based on equivalent boundary effect is presented in this paper. In the proposed scheme, the equivalent resonance component with a certain central frequency is sleeve-mounted at the beginning of protected zone. The 'Line Boundary' is built by using boundary effect, which is created by introducing impedance in the primary-side of line. The 'Line Boundary' is significantly different from line wave impedance. Therefore, the boundary protection principle can be applied to power distribution line without line traps. To analyze the frequency characteristic corresponding to traveling-waves of introducing impedance in the primary-side of line, distributed parameters model of equivalent resonance component is established. The results of PSCAD/EMTDC simulation prove the obvious difference of voltage high frequency component between internal faults and external faults due to equivalent resonance component, and validate the scheme.
An Improved Poincaré-like Carleman Linearization Approach for Power System Nonlinear Analysis
Wang, Zhou-Qiang ; Huang, Qi ; Zhang, Chang-Hua ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 271~281
DOI : 10.5370/JEET.2013.8.2.271
In order to improve the performance of analysis, it is important to consider the nonlinearity in power system. The Carleman embedding technique (linearization procedure) provides an effective approach in reduction of nonlinear systems. In the approach, a group of differential equations in which the state variables are formed by the original state variables and the vector monomials one can build with products of positive integer powers of them, is constructed. In traditional Carleman linearization technique, the tensor matrix is truncated to form a square matrix, and then regular linear system theory is used to solve the truncated system directly. However, it is found that part of nonlinear information is neglected when truncating the Carleman model. This paper proposes a new approach to solve the problem, by combining the Poincar
transformation with the Carleman linearization. Case studies are presented to verify the proposed method. Modal analysis shows that, with traditional Carleman linearization, the calculated contribution factors are not symmetrical, while such problems are avoided in the improved approach.
General Characteristic of Fractional Slot Double Layer Concentrated Winding Synchronous Machine
Seo, Un-Jae ; Chun, Yon-Do ; Choi, Jae-Hak ; Chung, Shi-Uk ; Han, Pil-Wan ; Koo, Dae-Hyun ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 282~287
DOI : 10.5370/JEET.2013.8.2.282
The concentrated winding configurations offer significant advantage for reducing end windings. These machines are generally used in low speed high torque application due to relatively low copper loss. However, numbers of fractional slot construction make the designer hard to properly choose pole and slot numbers for the certain application. This paper provides the general information of possible fractional slot concentrated double layer winding machine.
MUSIC-based Diagnosis Algorithm for Identifying Broken Rotor Bar Faults in Induction Motors Using Flux Signal
Youn, Young-Woo ; Yi, Sang-Hwa ; Hwang, Don-Ha ; Sun, Jong-Ho ; Kang, Dong-Sik ; Kim, Yong-Hwa ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 288~294
DOI : 10.5370/JEET.2013.8.2.288
The diagnosis of motor failures using an on-line method has been the aim of many researchers and studies. Several spectral analysis techniques have been developed and are used to facilitate on-line diagnosis methods in industry. This paper discusses the first application of a motor flux spectral analysis to the identification of broken rotor bar (BRB) faults in induction motors using a multiple signal classification (MUSIC) technique as an on-line diagnosis method. The proposed method measures the leakage flux in the radial direction using a radial flux sensor which is designed as a search coil and is installed between stator slots. The MUSIC technique, which requires fewer number of data samples and has a higher detection accuracy than the traditional fast Fourier transform (FFT) method, then calculates the motor load condition and extracts any abnormal signals related to motor failures in order to identify BRB faults. Experimental results clearly demonstrate that the proposed method is a promising candidate for an on-line diagnosis method to detect motor failures.
Digital Implementation of PWM Techniques for Two-phase Eight-switch Inverter fed Brushless DC Motor Drives
Lin, Hai ; You, Yong-Min ; Cheon, Sung-Rock ; Kwon, Byung-Il ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 295~303
DOI : 10.5370/JEET.2013.8.2.295
This paper reports an investigation of pulse width modulation (PWM) techniques for two-phase brushless DC (BLDC) motors fed by a two-phase eight-switch inverter in a fan application. The three-phase BLDC motor is widely applied in industry; however, a lower-cost two-phase BLDC motor and drive circuit has been greatly in demand in recent years. In this paper, we introduce a mathematical model of the two-phase BLDC motor with sinusoidal back electromotive forces (EMFs) based on traditional three-phase BLDC motors. To simplify the drive algorithm and speed up its application, we analyze the principle of block commutation for a two-phase BLDC motor drive in the 180-electrical-degree conduction mode, and we further propose five PWM schemes to improve the commutation performance of the two-phase BLDC drive. The effectiveness of the proposed PWM methods is verified through experiments.
Analysis of Cascaded H-Bridge Multilevel Inverter in DTC-SVM Induction Motor Drive for FCEV
Gholinezhad, Javad ; Noroozian, Reza ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 304~315
DOI : 10.5370/JEET.2013.8.2.304
In this paper, analysis of cascaded H-bridge multilevel inverter in DTC-SVM (Direct Torque Control-Space Vector Modulation) based induction motor drive for FCEV (Fuel Cell Electric Vehicle) is presented. Cascaded H-bridge multilevel inverter uses multiple series units of H-bridge power cells to achieve medium-voltage operation and low harmonic distortion. In FCEV, a fuel cell stack is used as the major source of electric power moreover the battery and/or ultra-capacitor is used to assist the fuel cell. These sources are suitable for utilizing in cascaded H-bridge multilevel inverter. The drive control strategy is based on DTC-SVM technique. In this scheme, first, stator voltage vector is calculated and then realized by SVM method. Contribution of multilevel inverter to the DTC-SVM scheme is led to achieve high performance motor drive. Simulations are carried out in Matlab-Simulink. Five-level and nine-level inverters are applied in 3hp FCEV induction motor drive for analysis the multilevel inverter. Each H-bridge is implemented using one fuel cell and battery. Good dynamic control and low ripple in the torque and the flux as well as distortion decrease in voltage and current profiles, demonstrate the great performance of multilevel inverter in DTC-SVM induction motor drive for vehicle application.
Asymmetric Cascaded Multi-level Inverter: A Solution to Obtain High Number of Voltage Levels
Banaei, M.R. ; Salary, E. ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 316~325
DOI : 10.5370/JEET.2013.8.2.316
Multilevel inverters produce a staircase output voltage from DC voltage sources. Requiring great number of semiconductor switches is main disadvantage of multilevel inverters. The multilevel inverters can be divided in two groups: symmetric and asymmetric converters. The asymmetric multilevel inverters provide a large number of output steps without increasing the number of DC voltage sources and components. In this paper, a novel topology for multilevel converters is proposed using cascaded sub-multilevel Cells. This sub-multilevel converters can produce five levels of voltage. Four algorithms for determining the DC voltage sources magnitudes have been presented. Finally, in order to verify the theoretical issues, simulation is presented.
Superconducting Magnet Power Supply System for the KSTAR 2
Plasma Experiment and Operation
Choi, Jae-Hoon ; Lee, Dong-Keun ; Kim, Chang-Hwan ; Jin, Jong-Kook ; Han, Sang-Hee ; Kong, Jong-Dae ; Hong, Seong-Lok ; Kim, Yang-Su ; Kwon, Myeun ; Ahn, Hyun-Sik ; Jang, Gye-Yong ; Yun, Min-Seong ; Seong, Dae-Kyung ; Shin, Hyun-Seok ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 326~330
DOI : 10.5370/JEET.2013.8.2.326
The Korea Superconducting Tokamak Advanced Research (KSTAR) device is an advanced superconducting tokamak to establish scientific and technological bases for attractive fusion reactor. This device requires 3.5 Tesla of toroidal field (TF) for plasma confinement, and requires a strong poloidal flux swing to generate an inductive voltage to produce and sustain the tokamak plasma. KSTAR was originally designed to have 16 serially connected TF magnets for which the nominal current rating is 35.2 kA. KSTAR also has 7 pairs of poloidal field (PF) coils that are driven to 1 MA/sec for generation of the tokamak plasma according to the operation scenarios. The KSTAR Magnet Power Supply (MPS) was dedicated to the superconducting (SC) coil commissioning and
plasma experiment as a part of the system commissioning. This paper will describe key features of KSTAR MPS for the
plasma experiment, and will also report the engineering and commissioning results of the magnet power supplies.
A New Sensitivity-Based Reliability Calculation Algorithm in the Optimal Design of Electromagnetic Devices
Ren, Ziyan ; Zhang, Dianhai ; Koh, Chang Seop ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 331~338
DOI : 10.5370/JEET.2013.8.2.331
A new reliability calculation method is proposed based on design sensitivity analysis by the finite element method for nonlinear performance constraints in the optimal design of electromagnetic devices. In the proposed method, the reliability of a given design is calculated by using the Monte Carlo simulation (MCS) method after approximating a constraint function to a linear one in the confidence interval with the help of its sensitivity information. The validity and numerical efficiency of the proposed sensitivity-assisted MCS method are investigated by comparing its numerical results with those obtained by using the conventional MCS method and the first-order reliability method for analytic functions and the TEAM Workshop Problem 22.
The Optimal Design of Single Sided PMLSM for Considering Winding Temperature Rising according to Thickness of Teeth
An, Ho-Jin ; Cho, Gyu-Won ; Woo, Seok-Hyeon ; Kim, Gyu-Tak ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 339~344
DOI : 10.5370/JEET.2013.8.2.339
This research deals with design of the maximum thrust density with considering winding temperature rise of single-sided PMLSM. The temperature rise of winding which caused to machine characteristics such as copper loss, iron loss and efficiency was analyzed by FEM. The maximum allowable current density was calculated within the allowable temperature. The effects of loss and efficiency according to temperature characteristic were confirmed.
Analysis of Surface Tracking of Micro and Nano Size Alumina Filled Silicone Rubber for High Voltage AC Transmission
Loganathan, N. ; Chandrasekar, S. ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 345~353
DOI : 10.5370/JEET.2013.8.2.345
This paper discusses the experimental results in an effort to understand the tracking and erosion resistance of the micro and nano size
filled silicone rubber (SIR) material which has been studied under the AC voltages, with ammonium chloride as a contaminant, as per IEC 60587 test procedures. The characteristic changes in the tracking resistance of the micro and nano size filled specimens were analyzed through leakage current measurement and the eroded masses were used to evaluate the relative erosion and tracking resistance of the composites. The fundamental, third and fifth harmonic of the leakage current during the tracking study were analyzed using moving average current technique. It was observed that the harmonic components of leakage current show good correlation with the tracking and erosion resistance of the material. The thermogravimetry-derivative thermo gravimetric (TG-DTG) studies were performed to understand the thermal degradation of the composites. The physical and chemical studies were carried out by using scanning electron microscope (SEM), Energy Dispersive X-ray analysis (EDAX) and Fourier Transform Infra-red (FTIR) Spectroscopy. The obtained result indicated that the performance of nano filled SIR was better than the micro filled SIR material when the % wt. of filler increased.
Investigation of SLF Interruption Capability of Gas Circuit Breaker with CFD and a Mathematical Arc Model
Cho, Yong-Sung ; Kim, Hong-Kyu ; Chong, Jin-Kyo ; Lee, Woo-Young ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 354~358
DOI : 10.5370/JEET.2013.8.2.354
This paper discusses the analysis of arc conductance in a gas circuit breaker (GCB) during current interruption process and the investigation method of the interruption capability. There are some limitations in the application of the computational fluid dynamics (CFD) for the implementation of an arc model around the current zero, despite the fact that it gives good results for the high-current phase arc. In this study, we improved the accuracy in the analysis of the interruption performance by attempting the method using CFD and a mathematical arc model. The arc conductance at 200 ns before current zero (G-200ns) is selected as the indicator to predict the current interruption of the Short Line Fault (SLF). Finally, the proposed method is verified by applying to the actual circuit breakers which have different interruption performances.
Switching Impulse Flashover Tests and Analysis for 765kV Jumper V-strings with Damaged Insulators
Choi, In-Hyuk ; Shin, Koo-Yong ; Lee, Dong-Il ; Lim, Jae-Sup ; Kim, Young-Hong ; Lee, Hyung-Kwon ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 359~363
DOI : 10.5370/JEET.2013.8.2.359
The 765kV transmission line will be maintained by live-line works for efficient operation. In order to maintain the 765kV transmission lines safely by live-line works, lineman has to know switching impulse flashover characteristics of the jumper V-strings with damaged insulators in advance. In order to know the flashover characteristics this paper carried out experimental flashover mockup tests for jumper V-string with damaged insulators in the outdoors. And it suggests flashover characteristics of the 765kV jumper V-strings also. The results will be used in estimating the safety of live working for 765kV transmission lines.
Investigation of Electromagnetic Field Coupling with Twisted Conducting Line by Expanded Chain Matrix
Cho, Yong-Sun ; Ro, Jong-Suk ; Chung, Yong-Seek ; Cheon, Changyul ; Jung, Hyun-Kyo ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 364~370
DOI : 10.5370/JEET.2013.8.2.364
In the current paper, we propose a new modeling algorithm to analyze the coupling between an incident electromagnetic field (EMF) and a twisted conducting line, which is a kind of non-uniform line. Typically, analysis of external field coupling to a uniform transmission line (TL) is implemented by the Baum-Liu-Tesche (BLT) equation so that the induced load responses can be obtained. However, it is difficult to apply this method to the analysis of a twisted conducting line. To overcome this limitation, we used a chain matrix composed of ABCD parameters. The proposed algorithm expands the dimension of the previous chain matrix to consider the EMF coupling effectiveness of each twisted pair, which is then applied to multi-conductor transmission line (MTL) theory. In addition, we included a comparative study that involves the results of each method applied in the conventional BLT equation and new proposed algorithm in the uniform two-wire TL case to verify the proposed method.
Compact UWB Bandpass Filter as Cascaded Center-Tapped CRLH Transmission-Line ZORs for Improved Stopband
Lee, Boram ; Kahng, Sungtek ; Wu, Qun ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 371~375
DOI : 10.5370/JEET.2013.8.2.371
The design of a new compact UWB bandpass filter is proposed, which has cascaded center-tapped microstrip composite right/left-handed transmission-line zeroth-order resonators (CRLH-TL ZORs). In an attempt to reduce the size, instead of the conventional half-wavelength resonators or periodic and multiple CRLH-TL cells, only one cell ZOR geometry is adopted as each resonator in the filter. Additionally, two center-tapped ZORs are coupled to increase the slope of the skirt. Besides, stepped impedance matching parts are placed in the paths to the input and output ports to enhance passband and stopband performances. The proposed filter is shown to have the overall size of
, the insertion loss much less than 1 dB, and an acceptable return loss performance in the predicted and measured results.
Real-Time Heart Rate Monitoring System based on Ring-Type Pulse Oximeter Sensor
Park, Seung-Min ; Kim, Jun-Yeup ; Ko, Kwang-Eun ; Jang, In-Hun ; Sim, Kwee-Bo ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 376~384
DOI : 10.5370/JEET.2013.8.2.376
With the continuous aging of the populations in developed countries, the medical requirements of the aged are expected to increase. In this paper, a ring-type pulse oximeter finger sensor and a 24-hour ambulatory heart rate monitoring system for the aged are presented. We also demonstrate the feasibility of extracting accurate heart rate variability measurements from photoelectric plethysmography signals gathered using a ring-type pulse oximeter sensor attached to the finger. We designed the heart rate sensor using a CPU with built-in ZigBee stack for simplicity and low power consumption. We also analyzed the various distorted signals caused by motion artifacts using a FFT, and designed an algorithm using a least squares estimator to calibrate the signals for better accuracy.
Uncalibrated Visual Servoing through the Efficient Estimation of the Image Jacobian for Large Residual
Kim, Gon-Woo ;
Journal of Electrical Engineering and Technology, volume 8, issue 2, 2013, Pages 385~392
DOI : 10.5370/JEET.2013.8.2.385
An uncalibrated visual servo control method for tracking a target is presented. We define the robot-positioning problem as an unconstrained optimization problem to minimize the image error between the target feature and the robot end-effector feature. We propose a method to find the residual term for more precise modeling using the secant approximation method. The composite image Jacobian is estimated by the proper method for eye-to-hand configuration without knowledge of the kinematic structure, imaging geometry and intrinsic parameter of camera. This method is independent of the motion of a target feature. The algorithm for regulation of the joint velocity for safety and stability is presented using the cost function. Adaptive regulation for visibility constraints is proposed using the adaptive parameter.